Usually, operating table systems have devices for releasable mounting of an accessory on, for example, a leg or back plate or an extension unit, by means of which broken bone parts are kept apart during the operation. Such a device comprises two coupling parts. One of these coupling parts is arranged on the accessory, while the other is mounted on the operating table. The two coupling parts can be connected to each other and thus form a mechanical interface for mounting the accessory on the operating table.
For securing the accessory, the connection between the two coupling parts has to be locked. This can be effected by a frictional connection, in that a locking element is actuated, for example, in that a knurled screw is tightened or an eccentric lever is thrown. This type of locking bears the risk that the operator forgets to actuate the locking element, and that the accessory inadvertently disengages from the operating table. In addition, it often happens that the locking element is not actuated with sufficient force so that only an insufficient frictional connection is established. In this case, too, the accessory can inadvertently disengage from the operating table.
A locking of the connection between the two coupling parts can also be effected by a positive locking. One example of such a positive locking is an arrangement in which a pin which is resiliently mounted on the one coupling part automatically engages the bore arranged on the other coupling part when the two coupling parts are connected to each other. Such a locking has the advantage that the operator is not obliged to actively actuate a locking element. There is further no risk that the operator forgets the locking operation. In order to remove the accessory from the operating table, the operator has to release the positive locking between the pin and the bore, i.e. unlock the connection between the two coupling parts.
For this purpose, mechanisms are known in which the operator actuates a corresponding element, for example, a push button or a spring-loaded lever, for unlocking. In this case, the connection is only unlocked for as long as the operator actuates the unlocking element.
Other mechanisms function such that one of two possible states, namely a locking state and an unlocking state, is assumed by actuation of an element, and this state is maintained for as long as this element is actuated again. Here, too, however, there is the risk that the operator forgets to re-activate the locking once he/she has unlocked the connection and, for example, exchanged the accessory. Moreover, since the operator has to activate the mechanism not only for unlocking but also for locking of the connection, the handling is comparatively time-consuming.
Conventional unlocking and locking mechanisms are problematic with respect to their handling in particular when the accessory has to be mounted and secured at two mechanical interfaces, as this is, for example, the case given a wide leg plate, on which both legs of the patient are to be rested at the same time and which is thus fixed at two points on the operating table. When the distance between these two points is so great that the operator cannot reach these points simultaneously with both hands, then removing of the accessory is particularly difficult. This also applies to the case where the accessory is comparatively bulky or heavy. Given such an accessory the removal from the operating table is already difficult when only one single mechanical interface is provided. In this case, for removing the accessory, it has to be grabbed near its center of gravity or at two points lying apart from one another as far as possible, since otherwise the accessory is levered out of the hands of the operator and thus there is no longer a possibility of unlocking.
Usually, an unlocking of the connection between the two coupling parts is only possible directly at the interface itself. A remote actuation or a coupled actuation of two interfaces is normally not possible. The reasons for this are space problems, cost considerations or operation-specific circumstances, such as the occurrence of disturbing contours in x-ray applications. In this case, the unlocking elements cannot be arranged at points which form ergonomically favorable points of application.